score/[id]

Normal defect. Blue mat appearance of obliquely oriented intersecting submucosal connective tissue fibres (indigo carmine or methylene blue)

Homogeneously stained, partially resected submucosa. Submucosal vessels may be exposed but are uninjured

Clip closure is not required for the defect itself

Muscularis propria (MP) visible but no mechanical injury (whale sign)

Completely resected submucosa. White unstained MP with circumferential striations, resembling the ventral pleats of a blue whale seen from underwater

MP was not present in any type I specimens in Burgess 2017

Clip placement is not required

Focal loss of the submucosal plane raising concern for MP injury or rendering the MP defect uninterpretable

Distinction between submucosa and MP is unclear, often due to poorly staining submucosal fibrosis

Clip all type II injuries. The only delayed perforation in Burgess 2017 was an unclipped type II defect

MP injured; specimen target sign (STS) or defect target sign (DTS) identified

Partial MP resection. DTS in the defect and/or STS on the underside of the specimen (white/grey disc encircled by blue-stained submucosa)

Clip closure of the DTS to prevent delayed perforation. Same-day discharge is often possible if the patient is well and closure is secure

Actual hole within a white cautery ring, no observed contamination

Complete hole / full-thickness resection of the MP. Concentric ring of cautery artefact. Clean, no faecal effluent

Close immediately. Where possible, complete resection of surrounding adenoma before clip placement

Actual hole within a white cautery ring, observed contamination

Full-thickness perforation contaminated by faecal effluent

Close the hole and obtain a surgical consultation. Acute surgery if clinical deterioration, peritonitis, significant free intraperitoneal fluid, or failed endoscopic resection

1 mL of 0.4% indigo carmine or methylene blue and 1 mL of 1:10 000 adrenaline combined with 8 mL saline (Burgess 2017)

Careful post-resection assessment of the defect. Topical submucosal chromoendoscopy (dye via a retracted injection catheter) may enhance contrast when the plane is unclear

Potential DMI is associated with increasing lesion size, submucosal fibrosis, and transverse colon location

Target signs or perforation are associated with en bloc resection, transverse colon location, and high-grade dysplasia or submucosal invasive cancer. Avoid en bloc EMR of lesions ≥25 mm when possible

Described for colonic EMR of laterally spreading lesions ≥20 mm. The same defect-assessment principles apply when a chromic injectate is used for ESD. Separate from the ESD-F (F0–F2) fibrosis grade